- Remove the liquid line connection cap.
- Then remove the suction connection cap.
- Open both valves midway.
- Care should be taken to avoid the holding charge from releasing too
quickly.
- Be sure tube fitting inner diameter and tube outer diameter are clean prior
to assembly.
- Recommended brazing materials: a copper / phosphorous or copper /
phosphorous / silver alloy rod should be used for joining copper to copper
whereas to join dissimilar or ferric metals, use a silver alloy rod, either flux
coated or with a separate.
- Use a double tip torch.
g. Start-up & Operation
Initial pressure test (by vacuum and nitrogen)
Step-by-step
• Use a 4-port gauge manifold with 3/8” hose and connections to the
vacuum pump. The vacuum gauge does not have to be connected for this
part of the process.
• Connect the gauges to service ports provided on receiver valve and suction
tube. In order to remove any non-condensable that may have entered the
system during installation, follow these steps:
• Start the vacuum pump. The evaporator fan should be running and the
compressor crankcase heater is energized at this point. This will involve
powering up the unit so it is important to disconnect the live feed wire to
the compressor contactor (so the compressor cannot run and the crank
case heater can be energized).
• Open both valves on the manifold and then open the main vacuum valve
on the pump. Run the system until the vacuum level of -0.85 bar (as read
on manifold gauge) is achieved.
• Shut off the main vacuum pump valve. Check for vacuum rise using the
manifold compound gauge. A rise would indicate a large leak.
• If vacuum holds for 10 minutes, break vacuum with Nitrogen. Check the
name plate of the unit / compressor for allowable leak test pressure.
Ensure that pressure regulators are installed on the Nitrogen cylinders.
Check for leaks and repair leakage.
End of tube
During brazing
protect housing with
damp cloth
During brazing
pull back fire
insulation
OUTSIDE
INSIDE UNIT
18
